The invention relates to interactive voice response (IVR) units that accept a combination of voice and/or touch tone inputs, and in response navigate the caller through menu options using pre-recorded messages. Such systems are well-known in general, but known systems do not alter the navigation logic based on current and/or historical call data. Thus, the same navigation logic is used for all callers, all the time, without taking into account any current and/or historical call data.